R&D Forum

Study predicts mixed bag of water availability on Pacific Coast

A precipitation analysis conducted by the U.S. Energy Information Administration (EIA) could have mixed meanings for hydroelectric power operators and providers along America's Pacific coast.

Using studies conducted by the Northwest River Forecast Center (NWRFC) and California Department of Water Resources (DWR), EIA said the water resources available for hydropower generation in California could be significantly higher in recent years, while resources in the Pacific Northwest are projected to be normal to below normal through September.

According to DWR, snowpack in the Sierra Nevada mountain range through the current water year (which ends Sept. 30) is at 94% of normal, with precipitation in December being twice the average. This represents a "significant departure from the prior year," EIA said, which was "significantly below normal."

EIA notes that California's hydro projects usually contribute 11% to 28% - record lows and highs achieved in 1992 and 1995, respectively - of the state's power supply, with production peaking in the spring and early summer when melting snow starts flowing through river basins.

Meanwhile, NWRFC reported that its water projects for April to September - typically the high hydro season - call for a normal to below-normal supply. NWRFC made its forecast by examining precipitation in a given period, snowpack held through a watershed, and subsequent runoff of snow melting in the watershed.

Overall, NWRFC said precipitation in October 2012 was 189% of normal but was countered by a January that was 66% of normal. Additionally, temperatures were too high in October for the extra precipitation to build snowpack, meaning current snowpack levels are only about average at most measuring stations.

EPRI releases report on fish survival after screen impingement

A new report, Post-Impingement Survival of Juvenile and Adult Fish with a Geiger Multi-Disc Screen: Laboratory Evaluations, is available from EPRI.

This report presents the results of a laboratory study evaluating the survival, injury and scale loss of fish exposed to the Passavant-Geiger Multi-Disc screen. EPRI says the data presented provide a basis upon which to estimate the potential for these screens to meet the proposed Environmental Protection Agency Clean Water Act Existing Facilities Rule as it relates to impingement mortality.

This rule, to be finalized in June 2013, includes modified traveling band screens as one option for meeting the impingement mortality reduction standard under the streamlined compliance approach. However, the extent to which new traveling screen designs will be included in the streamlined approach is not known. A laboratory evaluation was considered to be the only approach that could develop a substantial quantity of new data to assess the screen's performance compared with modified traveling band screens.

A Geiger screen was installed in a hydraulic test flume and six species of juvenile and adult fish of varying lengths were exposed to the impingement and collection process and then evaluated for survival, injury and scale loss. Two mesh types were used: 2-mm stainless steel and 9.5-mm drilled plastic. A total of 105 treatment and control replicates involving more than 24,600 fish were tested over 31 days. Median unadjusted survival rate for all species and velocities was 95.7%.

Data in the report can be used to inform the EPA rulemaking process, EPRI says.

BPA analyzing research proposals to improve Northwest system

The Bonneville Power Administration's Technology Innovation Office is analyzing proposals collected for energy research to develop technologies to improve operation of the hydroelectric system in the Pacific Northwest.

Since 2005, the Technology Innovation Office has funded projects to create a more efficient Northwest power system, with a recent focus on hydropower, energy efficiency, physical security and transmission services.